Upon clicking 'play' in the launcher, this crash report is displayed:

---- Minecraft Crash Report ----
// Who set us up the TNT?

Time: 11/21/14 9:40 PM
Description: Initializing game

org.lwjgl.LWJGLException: Could not create pixel format
at org.lwjgl.opengl.MacOSXPeerInfo.nChoosePixelFormat(Native Method)
at org.lwjgl.opengl.MacOSXPeerInfo.choosePixelFormat(MacOSXPeerInfo.java:58)
at org.lwjgl.opengl.MacOSXPeerInfo.<init>(MacOSXPeerInfo.java:53)
at org.lwjgl.opengl.MacOSXCanvasPeerInfo.<init>(MacOSXCanvasPeerInfo.java:61)
at org.lwjgl.opengl.MacOSXDisplayPeerInfo.<init>(MacOSXDisplayPeerInfo.java:48)
at org.lwjgl.opengl.MacOSXDisplay.createPeerInfo(MacOSXDisplay.java:323)
at org.lwjgl.opengl.DrawableGL.setPixelFormat(DrawableGL.java:61)
at org.lwjgl.opengl.Display.create(Display.java:846)
at org.lwjgl.opengl.Display.create(Display.java:757)
at org.lwjgl.opengl.Display.create(Display.java:739)
at bss.an(SourceFile:526)
at bss.ak(SourceFile:355)
at bss.a(SourceFile:302)
at net.minecraft.client.main.Main.main(SourceFile:124)

A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

– Head –
Stacktrace:
at org.lwjgl.opengl.MacOSXPeerInfo.nChoosePixelFormat(Native Method)
at org.lwjgl.opengl.MacOSXPeerInfo.choosePixelFormat(MacOSXPeerInfo.java:58)
at org.lwjgl.opengl.MacOSXPeerInfo.<init>(MacOSXPeerInfo.java:53)
at org.lwjgl.opengl.MacOSXCanvasPeerInfo.<init>(MacOSXCanvasPeerInfo.java:61)
at org.lwjgl.opengl.MacOSXDisplayPeerInfo.<init>(MacOSXDisplayPeerInfo.java:48)
at org.lwjgl.opengl.MacOSXDisplay.createPeerInfo(MacOSXDisplay.java:323)
at org.lwjgl.opengl.DrawableGL.setPixelFormat(DrawableGL.java:61)
at org.lwjgl.opengl.Display.create(Display.java:846)
at org.lwjgl.opengl.Display.create(Display.java:757)
at org.lwjgl.opengl.Display.create(Display.java:739)
at bss.an(SourceFile:526)
at bss.ak(SourceFile:355)

– Initialization –
Details:
Stacktrace:
at bss.a(SourceFile:302)
at net.minecraft.client.main.Main.main(SourceFile:124)

– System Details –
Details:
Minecraft Version: 1.8.1-pre5
Operating System: Mac OS X (x86_64) version 10.10.2
Java Version: 1.6.0_65, Apple Inc.
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Apple Inc.
Memory: 64643576 bytes (61 MB) / 165163008 bytes (157 MB) up to 1060372480 bytes (1011 MB)
JVM Flags: 5 total; -Xmx1G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
Launched Version: 1.8.1-pre5
LWJGL: 2.9.2
OpenGL: ~_ERROR~ RuntimeException: No OpenGL context found in the current thread.
GL Caps:
Using VBOs: No
Is Modded: Probably not. Jar signature remains and client brand is untouched.
Type: Client (map_client.txt)
Resource Packs: []
Current Language: ~_ERROR~ NullPointerException: null
Profiler Position: N/A (disabled)